Software application programs have long been used to perform tasks for computer users. For example, one type of software application programs supports collaboration in which multiple users at remote locations of a network can easily convey information to each other. In such a software application, a server disposed in the network typically maintains communication links with each of multiple clients that display respective collaboration windows (e.g., a whiteboard) to viewers. When one of the viewers modifies contents of his collaboration window, the server receives an indication of the changes and notifies all other collaboration windows of the changes so that each collaboration window in the network displays the same information to all users. Consequently, a user at a first remote location can communicate with one or more users at respective one or more other remote locations in the network and vise versa.
One type of information that can be displayed in a respective collaboration window is text. For example, a user can type in text at a respective collaboration window. As the user types the text, the collaboration server learns of the changes made to the respective user collaboration window by the user. To synchronize the collaboration windows, the server populates the other collaboration windows with the text typed in by the user so that each user views the same information.
Another type of information that can be displayed in a respective collaboration window is a picture. For example, a user can initiate inclusion of a digital picture in a respective collaboration window for viewing by all other users. In this case, to synchronize the collaboration windows, the server retrieves a copy of the newly added picture that is presented in the collaboration window and populates the other collaboration windows with the same digital picture so that each user again views the same information. The time and resources required to retrieve a copy of the picture and distribute it to the other users can be quite substantial since a single picture can be on the order of millions of pixels in resolution.